建立了一种检测咸鱼中亚硝酸盐含量的分光光度法。方法原理是亚硝酸盐与对氨基苯磺酸重氮化,再与N,N-二乙基苯胺偶联生成橙色产物,该产物在474nm处有最大吸收。在最佳实验条件下,亚硝酸根的浓度在0~10mg·L-1范围内成良好的线性关系,回收率为89%~92%。该方法测定咸鱼中亚硝酸盐的含量简单、快速、灵敏高,干扰小,测定结果与国标法基本一致。同时对咸鱼中亚硝酸盐的去除方法进行了研究,考察了超声提取葱、姜、蒜提取液及三者的混合提取液对亚硝酸盐的清除作用。结果表明：物料比分别为50g/100g、30g/100g、30g/100g葱、姜、蒜在60℃下,超声40min的后的提取液对亚硝酸盐清除效果最好,蒜、姜、葱的清除率分别为63．6%,56．6%,54．6%。蒜含量不小于50%的蒜、葱、姜混合浸提液对亚硝酸盐的清除效果优于纯的葱、姜、蒜。且葱、姜、蒜提取液的比例为1：4：5时清除率最高。不同腌制时间的咸带鱼经过混合浸提液浸泡后,去除率在69．8%~95．5%范围内,清除效果很好。%A new spectrophotometric method was established for determination of nitrite in salted fish. The method is based on a di-azotion-coupling reaction between nitrite and P-amino benzene sulfonic acid,then coupling with N,N-diethylaniline to form an or-ange product. The liner range for determination of sulfite was found to be 0~10mg·L-1 with a correlation coefficient of 0. 9976. The recoveries were in the range of 89~92%. This method has simple operation,good selectivity,high sensitivity and little interference. The results comparing with the standard method are basically the same. The method of nitrite scavenging in salted fish were studied, too. The scavenging effect of welsh onions、ginger、garlic extraction on nitrite in salted fish were studied. The result show that the opimum ultrasonic hath temperature,sonication time were 60℃,40min. And the solid and liquid of welsh onions、ginger、garlic were 50g/100g、30g/100g、30g/100g. Under the best conditions, the scavenging radio of welsh onions、ginger、garlic were 54. 6%, 56. 6%,63. 6%. When the extraction of garlic is not less then 50%,the scavenging were higher than the three kinds of material. The scavenging radio of the mixture of 1mL welsh onions,4mL ginger and 5mL garlic is the highest. After the salted fish weresoaked in the mixture,the scavenging radio of nitrite were found in the range of 69. 8% ~95. 5%.
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